Eliminating Clover and Crabgrass in a New Pennsylvania Lawn

A PA homeowner planted mixed grass (mostly bluegrass) less than a year ago; now clover and crabgrass are rampant in 90°F heat. They have a hose-end weed killer and plan to spray after rain in evening.

Different Weeds, Different Tactics

Clover (Broadleaf Perennial)

• Use broadleaf herbicide (2,4-D, MCPP, dicamba, or combos) on actively growing clover.
• Best in early-mid fall; spring less effective, summer risky (>85°F).
• Spot-treat if possible; wait 4 mowings on new seed, 30 days before seeding after treatment.

Crabgrass (Annual Grass)

• Prevent with dense turf (mow 2.5–3 inches, proper fert/water).
• Pre-emergent herbicide (e.g., Scotts Halts) in early spring before soil hits 52–54°F nights (forsythia bloom time).
• Post-emergent control is difficult; prevention is key.

Action Plan

1. Early Sept: broadleaf herbicide for clover.
2. Wait 30 days; overseed bare spots.
3. Early next spring: pre-emergent for crabgrass.
4. Maintain dense lawn to prevent return.

Warning on Current Product

If it's non-selective (Roundup), it kills everything—only use where you want total kill. If selective, ensure it matches above categories and timing.